refactor: remove `I` prefix for interfaces in the code"

Description

Issue: [code consistency]: Remove `I` prefix for inter... (#56 - closed)

I've organized the most important changes by commits:

• remove I prefix for interfaces and update relevant imports
• update implementation classes that have naming conflicts post change to have the Default prefix

Note that eslint rule will be added in a separate MR as this one's already very chunky 🍫 .

Screenshots

These changes don't affect the UI. I've done a quick smoke test to ensure that the Web IDE is running as expected with the Example App.